The present invention relates to a frame member for a vehicle which is configured to have its longitudinal direction which extends in a vehicle longitudinal direction and have a closed cross section.
In a frame member of a vehicle, such as an automotive vehicle, which constitutes a vehicle body, such as a side sill, the high strength-and-rigidity is required to secure the safety of a passenger in a vehicle collision, and also the lightweight is required to improve the fuel-economy (gas millage) performance. Accordingly, the frame member is generally configured to have a closed cross section. Further, the frame member is configured such that a reinforcing member is attached inside a closed-cross-section shaped frame body for reinforcing the frame body in order to suppress buckling of the frame member, for example.
Japanese Patent Laid-Open Publication No. H11-255048 (FIG. 6A), for example, discloses a frame member, in which a bending portion is provided at a plate-shaped reinforcing member which interconnects one side face of a rectangular-shaped frame body and the other side face which faces the one-side face, and a plate-shaped support member is provided to extend from the bending portion of the reinforcing member toward an upper face of the frame member which is adjacent to the above-described side faces.
Herein, in the frame member disclosed in the above-described patent document, the frame member has two-stage buckling with a fulcrum of the bending portion which occurs when a load is inputted to the frame member from the above-described one-side-face side. The above-described patent document, however, does not refer to specific studies about a two-stage buckling manner of the frame member, and there is room for improvement on the mass efficiency of EA (Energy Absorption) against a collision.